Research paperPrevalence of cognitive decline and associated factors in elderly type 2 diabetic patients at inclusion in the GERODIAB cohort

ObjectiveThe GERODIAB follow-up survey is the first French multi-centre, prospective, observational study designed to analyze the influence of glycaemic control on morbidity-mortality over 5 years in type 2 diabetic patients aged 70 years and over. This report analyses the factors associated with cognitive decline at inclusion.Patients and methodsA total of 987 patients with well-maintained autonomy were consecutively included in 56 French diabetic centres. Cognition was systematically explored using the Mini-Mental State Examination (MMSE). Cognitive disorders were defined by previously known dementia and/or MMSE scores ≤ 24/30. Results were analyzed using the Kruskal-Wallis or the chi2 tests. Multivariate analysis was a stepwise logistic regression.ResultsTwo hundred and eighty-four patients (28.8%) had a cognitive disorder; they were older (78.4 ± 5 vs. 76.5 ± 4.8 year; P < .001) and were more frequently women (60.2 vs. 48.8%; P < .001). They had a similar duration of diabetes (17.6 ± 11.1 vs. 17.9 ± 10.7 years; P = .651), but a higher HbA1c level (7.8 ± 1.5 vs. 7.5 ± 1.2%; P = .002). They were treated with insulin more often (65.1% vs. 54.3%; P = .002) and less often with metformin (40.1% vs. 52.3%; P < .001). In multivariate analysis, cognitive disorders were associated with age, gender and HbA1c, successively (concordance 64.1%, P < .001). Of the complications of diabetes, cognitive impairment was associated with peripheral neuropathy (37.3 vs. 24.5%; P < .001), cerebrovascular involvement (20.8 vs. 13.8%; P = .007) and heart failure (14.1 vs. 8.5%; P = .009).ConclusionCognitive disorders were associated with HbA1c level and some complications of diabetes, suggesting similar pathological mechanisms. Systematic screening for cognitive impairment could be beneficial in elderly type 2 diabetic patients.